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Persistent Orbital Degeneracy in Carbon Nanotubes

A. Makarovski·L. An·J. Liu·G. Finkelstein
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Abstract

The quantum-mechanical orbitals in carbon nanotubes are doubly degenerate over a large number of states in the Coulomb blockade regime. We argue that this experimental observation indicates that electrons are reflected without mode mixing at the nanotube-metal contacts. Two electrons occupying a pair of degenerate orbitals (a ``shell'') are found to form a triplet state starting from zero magnetic field. Finally, we observe unexpected low-energy excitations at complete filling of a four-electron shell.

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A. Makarovski, L. An, J. Liu, G. Finkelstein. 2006-08-25. Persistent Orbital Degeneracy in Carbon Nanotubes. https://doi.org/10.1103/physrevb.74.155431

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